滇西楚雄盆地上三叠统云南驿组二段碳酸盐微相及沉积相分析

上三叠统云南驿组二段发育了一套较为完整的海相碳酸盐岩,对研究此处沉积环境具有重要意义。采用微相分析的方法,对本套碳酸盐岩的生物组合、微相类型和沉积环境进行研究,将树苴水泥厂处的云南驿组二段沉积归纳为8种微相:砂屑砾屑灰岩、含生物碎屑砂砾屑灰岩、介壳灰岩、含完整化石的泥-微晶灰岩、含生物碎屑泥晶-微晶灰岩、含生物碎屑砂屑球粒灰岩、含有机质纹层状泥晶-微晶灰岩、无纹层无化石泥晶-微晶灰岩。碳酸盐岩微相类型的垂向序列指示了此处云南驿组二段形成于海相斜坡环境及盆地边缘相沉积环境。

Carbonate Microfacies and Sedimentary facies analysis in the second member of the Yunnanyi Formation of Upper Triassic in Chuxiong Basin, West Yunnan

the second member of the Yunnanyi Formation of Upper Triassic developed a relatively integrated marine carbonate. Microfacies analysis are used in the study of biologic assemblage, microfacies types and sedimentary environment of the Carbonate. And summarized the limestone of second member of the Yunnanyi Formation into eight types of microfacies:arene calcirudite, arene calcirudite with clastizoic, shelly limestone, cryptite/calcipulverite with complete fossil, cryptite/calcipulverite with clastizoic, arene pelletal limestone with clastizoic, lamellar cryptite/lamellar calcipulverite with organic material, cryptite/calcipulverite without lamina and fossil.Vertical sequence of Carbonate Microfacies indicates the second member of the Yunnanyi Formation are formed in marine slope facies environment and basin margin environment.